MP Henry Bellingham has written to Patrick McLoughlin calling for plans to dual the trunk road to be announced in the autumn, with smaller schemes introduced on dangerous stretches of the road, such as in the west Norfolk village, in the short term.

The North West Norfolk MP is taking action after Jeffrey and Marion Hain and their son, Christopher, died after their Kia Cee’d car was involved in a crash with a lorry near King’s Lynn.

It comes amid a campaign by business leaders and politicians to get the trunk road – which stretches from Great Yarmouth into the Midlands, dualled.

The Highways Agency – which is responsible for the road – is currently working on a feasibility study to calculate if upgrading the road would be good value for money and it is expected to report back later this year.

Mr Bellingham said in his letter: “The only way in which safety can be really significantly improved on this road is through installing more dual carriageway.

“This brings me on to the pressing priority for an announcement in the Autumn Statement of at least one major dualling scheme on this key trunk road.

“This will not only improve safety but also help to underpin our local economy.”

He added: “In the meantime I am also very keen to see some immediate, short term improvements to the stretch through East Winch where the tragic accident happened.

“For example, I would like to see the current 50 mph limit reduced to 40.

“Furthermore, this should be reinforced with some new fibre-optic flashing signage that can alert drivers about their speed, potential hazards, junctions etc.”

Broadland MP Keith Simpson said: “It is very sad news.

“It is just more evidence that various parts of the A47 are very dangerous and it reinforces our campaign to get it dualled.”

A Department for Transport spokesman said: “Earlier this year we met with local authorities and enterprise partnerships to get their views on the scope of the A47 feasibility study, which we are currently considering.

“We expect to report back at Autumn Statement 2014 with solutions to the problems on this route.”